PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.

The UK Medical Eligibility Criteria (UKMEC) for contraceptive use (latest version 2009) are based on that published by the World Health Organization (WHO). They set out cautions and contra-indications for contraceptive use. Categories are as follows:

Category 1: a condition for which there is no restriction for the use of the contraceptive method.

Category 2: a condition for which the advantages of using the method generally outweigh the theoretical or proven risks.

Category 3: a condition for which the theoretical or proven risks of using the method generally outweigh the advantages. The method is not usually recommended.

Category 4: a condition which represents an unacceptable risk to health if the method is used.

Contra-indications

Women with a body mass index (BMI) ≥35 kg/m2 should normally avoid combined hormonal contraception. This includes the combined oral contraceptive pill (COCP) the contraceptive patch and the vaginal ring. For combined hormonal contraception, UKMEC category 3 is applied for these women, meaning that for most women the risks - primarily the increased risk of venous thromboembolism (VTE) - outweigh the benefits.

Women with a BMI ≥30 but under 35 are categorised as UKMEC category 2 for combined hormonal contraception, so for most women the benefits will outweigh the risk. In these women, consider the other risk factors carefully and consider other contraceptive options.

All other contraceptive options are considered safe in overweight or obese women.

Efficacy

There have been queries regarding whether hormonal contraception is less effective in women with higher BMI. The latest Cochrane review suggests there is no convincing evidence for this and that there is no need to adjust dose or regime according to weight. However, it notes that the quality of evidence is poor and limited and that more trials are needed.[2]

Other weight-related issues

Diaphragms and caps should be checked if the woman gains or loses 3 kg or more in weight.

In overweight women the progestogen-only contraceptive implant may need to be removed earlier than the licensed three years.[3] This is a recommendation from the manufacturer but there is no definite evidence for this. The Cochrane review mentioned above did not find evidence for this view.

Medication which induces liver enzymes can reduce the efficacy of combined hormonal contraception, progestogen-only contraception pills (POCPs) and implants but do not appear to reduce the efficacy of progestogen-only injectables or the levonorgestrel-releasing intrauterine system (LNG-IUS).

Combined hormonal contraception

COCP - all women should be advised to switch to a contraceptive method unaffected by enzyme inducers (eg, progestogen-only injectable, copper intrauterine device (Cu-IUCD) or LNG-IUS). Rifampicin and rifabutin are such potent enzyme-inducing drugs that extra contraceptive precautions or a switch are essential.

If the woman does not wish to change:

If on a short-term course of an enzyme-inducing drug (not rifampicin and rifabutin):

She should take a combination of oral contraceptives to provide a daily intake of ethinylestradiol 50 micrograms or more (unlicensed use), using an extended or tricycling regimen with a pill-free period of no more than four days, continued for the duration of the course and for four weeks afterwards. Breakthrough bleeding may indicate inadequate oestrogen levels - the dose can be increased to a maximum of ethinylestradiol 70 micrograms.

If she stays on her previous COCP, she should take extra contraceptive precautions (eg, sheath) for the duration of the course of enzyme inducer and for four weeks afterwards.

Long-term course of an enzyme-inducing drug:

Rifampicin and rifabutin are such potent enzyme-inducing drugs that an alternative method of contraception is always recommended.

Take a combination of oral contraceptives to provide a daily intake of ethinylestradiol 50 micrograms or more (maximum 70 micrograms) - unlicensed use.

Tricycling (taking three or four packets without a break followed by a short tablet-free interval of four days) is recommended.

Appropriate contraceptive measures are required for four weeks (the British National Formulary (BNF) says eight weeks) after stopping the enzyme-inducing drug.

Contraceptive patches:

Additional contraceptive precautions are required whilst taking the enzyme-inducing drug and for four weeks after stopping.

If concomitant administration runs beyond the three weeks of patch treatment, a new treatment cycle should be started immediately without a patch-free break.

For women taking long-term enzyme-inducing drugs, another method of contraception should be considered.

Progesterone only contraceptive pill (POCP)

Advise alternative contraceptive methods.

Progestogen-only implants

Women may continue with progestogen-only implants with additional contraceptive protection, such as condoms, when taking liver enzyme inducers and for four weeks after they are stopped.

Emergency contraception

Take a total dose of 3 mg levonorgestrel as a single dose as soon as possible and within 72 hours of unprotected sex.

Use of ulipristal acetate (UPA) is not advised in women using enzyme-inducing drugs or in those who have taken them in the preceding 28 days.

Migraine with aura

For all other forms of hormonal contraception (ie POCP, injectables, implants and the LNG-IUS) it is category 2. Benefit generally outweighs risks.

A past history of migraine with aura (where the last migraine occurred five or more years previously) is a category 3 for combined hormonal contraception. For other methods of hormonal contraception it remains a category 2 condition.

Migraine without aura

Migraine without aura is a UKMEC category 2 when considering starting combined hormonal contraception. However, if migraine without aura develops whilst on combined hormonal contraception, this becomes category 3 and an alternative form of contraception should be considered.

Other forms of hormonal contraception are category 1 or 2 and are considered safe to use.

Women with diabetes with complications (nephropathy, retinopathy, neuropathy or any other vascular disease) should usually not have the following methods of contraception, which are UKMEC category 3 or 4:

The contraceptive implant is category 1, ie no restriction for use in women with diabetes.

Other hormonal methods of contraception are UKMEC category 2 and therefore considered generally safe to use.

For women with diabetes and no complications, any contraceptive method is considered safe to use. However, should complications develop, reconsider contraceptive choice if she is using combined hormonal contraception or progestogen-ony injections.

Broadly speaking, women with hypertension, controlled or otherwise, should not have combined hormonal contraception but should consider another contraceptive choice. Where there is associated vascular disease, injectable progestogens are UKMEC category 3. Other hormonal and non-hormonal methods of contraception are acceptable.

More specifically:

For women with hypertension that is adequately controlled, or with consistently increased systolic blood pressure over 140 mm Hg and below 160 mm Hg, or diastolic blood pressure over 90 mm Hg and below 95 mm Hg, without vascular disease:

There are restrictions in the use of hormonal contraception for women with multiple risk factors for cardiovascular disease such as:

Older age

Smoking

Diabetes mellitus

Hypertension

Obesity

Where this is the case, combined hormonal contraception is UKMEC category 3/4, so these women should choose another method of contraception. Injectable progestogens are also not advisable for these women (category 3). All other hormonal methods may be used.

Women with VTE or a risk of VTE may use all methods of contraception other than combined hormonal contraception.

Broadly, women with VTE, a history of VTE or at risk of VTE should not use combined hormonal contraception (COCP, contraceptive patch or vaginal ring). Specifically:

History of VTE whether on anticoagulants or not: UKMEC category 4.

Family history of VTE in a first-degree relative under the age of 45: UKMEC category 3 (If first-degree relative was aged 45 or over when they had a VTE, the category becomes 2 and the risk may outweigh the benefit, if no other risks).

Women with current pelvic inflammatory disease: cu-IUCDs and the LNG-IUS should not be inserted. There is generally no need for removal if the woman wishes to continue their use.

Women with a current purulent cervicitis, chlamydial infection, or gonorrhoeal infection: cu-IUCDs and the LNG-IUS should not be inserted. There is generally no need for removal if the woman wishes to continue their use.

HIV is not a contra-indication in itself for most forms of contraception but certain antiretroviral therapies may be. Furthermore, barriers and caps are UKMEC category 3 for those known to have, or at high risk of, HIV/AIDS. This is because there is evidence that repeated high-dose use of the spermicide nonoxynol-9 is associated with increased risk of genital lesions, which may increase the risk of acquiring HIV. Safe sex and contraception for people with HIV is usually a matter for specialist advice.

For women with learning disabilities there is high use of injectable contraceptives and IUCDs. However, management of contraceptive needs of young women with an intellectual disability is similar in most cases to the management of non-disabled women.

A person with learning disability or mental impairment may be competent to make an informed choice regarding method of contraception and be able to use any method reliably. An assessment of competence to consent to treatment should be made.

It is therefore essential to consider the individual circumstances and wishes of women with learning disabilities and not necessarily opt for those methods that do not require the understanding and involvement of the user.

A woman with an intellectual disability may need the assistance of an experienced worker to fully explain contraceptive options in order to make an informed choice. She should be supported in making her own decision.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.